Incandescent electric lamp



' (No Model.;

J. W. BENSON.

INOANDESOENT ELECTRIC LAMP. No. 307,166. I Patented 001:. 28, 1884.

v WITNESSES:

ATTORNEYS.

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I UNITED STATES PATENT OFFICE.

JAMES WALTER BENSON, OF NORTH ADAMS, MASSACHUSETTS.

INCANDESCENT ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 307,166, dated October 28, 1884.

Application filed November 16, 1883. (No model.)

To all whom, it may concern Be it known that I, JAMEs'WALTER BEN- SON, of North Adams, in the county of Berkshire and State of Massachusetts, have invented a new and useful Improvement in Incandescent Electric Lamps, of which the fol-.

lowing is a full, clear, and exact description.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar letters of reference indicate corresponding parts in all the figures.

Figure 1 isa side elevation of my improvement shown as applied to the holder and globecap of an incandescent electric lamp. Fig. 2 is an elevation of the same, turned one-quarter around, and partly in section. Fig. 3 is a sectional plan view oi'the same, taken through the line x a, Fig. 2. Fig. 4 shows a modified form oflocking device applied to the cap and holder.

The object of this invention is to prevent the accidental loosening of the globe from the holder and the accidental detachment of the globe.

The invention consists in an incandescent electric lamp constructed with a spring-pawl attached to the globe-cap and engaging with ratchetteeth formed upon the outer surface of the insulating-ring, whereby the said globe will be locked against accidental displacement, as will be hereinafter fully described.

A represents the supporting rod or bracket. B is the holder. 0 is the key for opening and closing the circuit. D is the globe, and E is the globe-cap, which is connected with the holder B by a ring, F, of wood or other suitable non conducting material.

As thus far described there is nothing new in the construction.

Upon the outer surface of the insulatingring F are formed ratchet-teeth G, with which 40 engages a spring-pawl, H, attached to the cap E, so that the globe-capEcannot become loosened in the holder B, and thus break the electric connection, and so that the globe cannot become accidentally disconnected and fall. The same thing can be accomplished by a spring-catch working in holes in the outer surface of the insulating'ring, as shown in Fig.4; but I prefer the construction first described as being simple, convenient, and reliable.

Having thus described myinvention, Iclaim as new and desire to secure by Letters Patent- 1. The combination of the globe-cap E, provided with a screw-threaded extension, and a spring locking device secured to said cap,with 5 the holder B, and insulating-ring F, secured therein,the said insulating-ringbeing provided with internal screw-threads and with external irregularities in its surface, whereby when the capis screwed into said ring to the desired dis- 6o tance it will be prevented from unscrewing by the engagement of the spring locking device with the insulating-ring, substantially as set forth.

2. In an incandescentelectriclanip, the combination, with the globe-cap E and the insulating-ring F, having ratchet-teeth G, of the spring-pawl H, substantially as herein shown and described, whereby the said globe will be secured against accidental displacement, as set forth.

JAMES WALTER BENSON.

Witnesses:

JARVIS RooKwELL, JAS. E..HUNTER. 

